The present invention relates to an arrangement for a steering system for a vehicle. More particularly, the invention relates to a method and arrangement that permits efficient mounting of a steering system in a passenger car.
In a motor vehicle, exemplarily a passenger car, a steering system is typically utilized to steer the front wheels of the vehicle. Such a steering system normally includes a steering wheel and an upper main shaft on which the steering wheel is arranged. The upper main shaft is suitably mounted so that it extends through a specially designed steering column which is in turn suspended in the body of the vehicle, specifically on the underside of the dashboard.
The steering column can be designed so that it absorbs energy in the event that the steering wheel and the upper main shaft are acted on by great force in the direction towards the front of the vehicle; a situation which can occur if the vehicle is involved in a crash. This can happen in such a situation if the driver of the vehicle is thrown forwards with great force; a force that can be transmitted to the steering wheel and the upper main shaft. By adapting the steering column so that it absorbs energy, the upper main shaft is allowed to move a certain distance in relation to the steering column to absorb energy. This, in turn, reduces the stresses experienced by the driver in the course of a collision.
Furthermore, the upper main shaft extends through a guide passage in the intermediate panel of the vehicle and is connected to a lower main shaft via a joint. The lower main shaft is in turn connected to a steering gear arranged in the vehicle via a further, lower joint. In this way, the movements of the steering wheel can be transmitted via the upper and the lower main shaft, and on to the steering gear. In modern vehicles, the steering gear is usually of the rack-type variety which comprises an input shaft in the form of a pinion with a gear drive which is connected to a rack. The movements of the steering wheel cause a rotary movement of the pinion that acts on the rack which, in turn, acts on separate steering connecting rods. It is in this way that the steering wheels of the vehicle are turned.
When a steering system is mounted in a passenger car, the upper main shaft is first arranged in position in the above-mentioned steering column. The steering column is then mounted on the underside of the dashboard of the vehicle. In this situation, it is a prerequisite that the lower main shaft be mounted beforehand on the upper main shaft via a joint. This results in the lower main shaft, after the steering column has been mounted, hanging down from this joint. The mounting procedure is then completed by the lower main shaft being mounted firmly on the steering gear, which is carried out by a fitter-technician who stretches under the dashboard, takes hold of the lower main shaft, and connects it together with the lower joint, which in turn is connected to the steering gear. This is an awkward operation for the technician because the working area is not easily accessible. Usually, the technician cannot see where the lower main shaft is located, and therefore has to feel his/her way forward under the dashboard in order to take hold of the lower main shaft and mount it firmly in the correct manner. A further disadvantage of known mounting procedures as described hereinabove, is that it is relatively time-consuming.
In view of the above described deficiencies associated with conventionally designed steering arrangements and installation procedures therefore, the present invention has been developed. These enhancements and benefits are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.
The present invention in its several disclosed embodiments alleviates the drawbacks and deficiencies described above with respect to conventionally designed steering arrangements and their methods of installation; the invention further incorporates several additional beneficial features which will become evident to those skilled in the art from the following description.
In one aspect, the present invention provides an improved arrangement for a is steering system for a vehicle, in which the above-mentioned problems are solved and which provides simple mounting and a safe interconnection between a main shaft and a steering gear.
Further, the invention provides a method for automatic mounting of a steering system in a motor vehicle; in particular, it enables simple and cost-effective mounting of the steering system in the vehicle.
An arrangement, according to the invention, may take the form of a steering system for a vehicle that includes a steering wheel and a main shaft which is connected to the steering wheel and also suspended in the vehicle. The main shaft is connected to a steering gear which belongs to the steering system and which has an input shaft for transmission of rotary movement of the main shaft to the steering gear. The arrangement is configured so that that end portion of the main shaft facing the input shaft terminates in a first deformation adapted for locking interaction with a second deformation in the input shaft; this locking interaction being accomplished when rotary movement is transmitted to the steering gear.
A number of advantages are achieved by virtue of the fact that the main shaft can be mounted on the input shaft by way of the above-mentioned deformations. For example, a good ergonomic situation is afforded for the fitting technician who is charged with mounting the steering system into the vehicle; exemplarily, in a case where the invention is used in connection with manual mounting. The invention also affords rapid and simple mounting of a steering system, which is inexpensive in process terms. Moreover, the invention is cost-effective in production terms because the above-mentioned deformations can be produced easily by, for example, casting and milling.
A major advantage of the invention is that it can be used in connection with an automated production process for motor vehicles. In such an assembly process, a robot can be programmed to take hold of a lower main shaft and guide it into position on the pinion. A locking sleeve can then be automatically screwed tightly thereon by the robot so that the connection is secured.
The beneficial effects described above apply generally to the exemplary devices, mechanisms and methods/processes disclosed herein for the mounting of a steering system in a transporting vehicle. The specific structures and steps through which these benefits are delivered will be described in greater detail hereinbelow.